Biology

Qwilfish is a sea dwelling Pokémon with a spherical body and a flat, paddle-shaped tail. The upper-half of its body is dark teal and the lower half is very light yellow. Its tail is tall and thin with a dark teal outline, light yellow inside, and two dark teal dots in the center. Its eyes are even with its body, and are always seen slanted angrily. Below its eyes are its puffy pink lips. All around its body are sharp, conical spikes, which evolved from scales over time. In order to attack, Qwilfish drinks 2.6 gallons of water to inflate its body. It then uses the water pressure to shoot poisonous quills at its foe. Due to its round body, Qwilfish is not a great swimmer, and when filled with water it is even harder for it to swim.

In the manga

In the Pokémon Adventures manga

A swarm of Qwilfish appeared in Querulous Qwilfish, angered by pollution that occurred as a result of an accident that occurred during the construction of the Battle Tower. Crystal captured all of them with her skills. Afterwards she found a baby Qwilfish stuck in the toxic waste, which it and the sea were cured and cleaned up respectively. It is unknown if they are still under Crystal's ownership or were released back afterwards.